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1.
Inorg Chem ; 2021 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-34779197

RESUMO

Antiperovskites are a promising candidate structure for the exploration of new materials. We discovered an antiperovskite phosphide, LaPd3P, following our recent synthesis of APd3P (A = Ca, Sr, Ba). While APd3P and (Ca,Sr)Pd3P were found to be tetragonal or orthorhombic systems, LaPd3P is a new prototype cubic system (a = 9.0317(1) Å) with a noncentrosymmetric space group (I4̅3m). LaPd3P exhibited superconductivity with a transition temperature (Tc) of 0.28 K. The upper critical field, Debye temperature, and Sommerfeld constant (γ) were determined to be 0.305(8) kOe, 267(1) K, and 6.06(4) mJ mol-1 K-2 f.u.-1, respectively. We performed first-principles electronic band structure calculations for LaPd3P and compared the theoretical and experimental results. The calculated Sommerfeld constant (2.24 mJ mol-1 K-2 f.u.-1) was much smaller than the experimental value of γ because the Fermi energy (EF) was located slightly below the density of states (DOS) pseudogap. This difference was explained by the increase in the DOS at EF due to the approximately 5 atom % La deficiency (hole doping) in the sample. The observed Tc value was much lower than that estimated using the Bardeen-Cooper-Schrieffer equation. To explain the discrepancy, we examined the possibility of an unconventional superconductivity in LaPd3P arising from the lack of space inversion symmetry.

2.
Surg Today ; 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34668052

RESUMO

PURPOSE: In recent years, the expectations for telesurgery have grown with the development of robot-assisted surgical technology and advances in communication technology. To verify the feasibility of the social implementation of telesurgery, we evaluated the communication integrity, availability, and communication delay of robotic surgery by remote control under different communication conditions of commercial lines. METHODS: A commercial line was used to connect hospitals 150 km apart. We had prepared guaranteed-type lines (1Gbps, 10Mbps, 5Mbps) and best effort-type lines. Two types of robotic teleoperations were performed, and we evaluated the round-trip time (RTT) of communication, packet loss, and glass-to-glass time. RESULTS: The communication delay was 4 ms for the guaranteed-type line and 10 ms for the best effort-type line. Packet loss occurred on the 5 Mbps guaranteed-type line. The mean glass-to-glass time was 92 ms for the guaranteed-type line and 95 ms for the best effort-type line. There was no significant difference in the number of errors in the task according to the type of line or the bandwidth speed. CONCLUSIONS: The social implementation of telesurgery using the currently available commercial communication network is feasible.

3.
Phys Chem Chem Phys ; 23(35): 19827-19833, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34525149

RESUMO

We investigated the defect structures of polycrystalline CaKFe4As4 (CaK1144) superconductors by scanning transmission electron microscopy (STEM). The STEM studies revealed the presence of a one-layer CaFe2As2 (∼1 nm size) defect along the ab-plane, as observed in single crystalline CaK1144. Step-like CaFe2As2 defects are also observed. These nanoscale defects generate fine-sized stacking faults, a lattice mismatch, and stress field defects in the matrix of CaK1144 owing to the different sizes. Correlation of the defects in polycrystalline and single crystalline samples suggests that the defects type and their density depend on the synthesis conditions. A self-field critical current density (Jc) of 15.2 kA cm-2 was obtained at 5 K, and the curves were sustained above 30 K with a considerable Jc value of 1.4 kA cm-2. We investigated the relationship between the observed intrinsic defects and the behavior of the field dependence of Jc. The intrinsically intergrown planar defects, even in polycrystalline samples, are expected to be advantageous for various high-field applications of bulk CaK1144 superconductors.

4.
Proc Natl Acad Sci U S A ; 118(37)2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34493664

RESUMO

Magnetic superconductors are specific materials exhibiting two antagonistic phenomena, superconductivity and magnetism, whose mutual interaction induces various emergent phenomena, such as the reentrant superconducting transition associated with the suppression of superconductivity around the magnetic transition temperature (T m), highlighting the impact of magnetism on superconductivity. In this study, we report the experimental observation of the ferromagnetic order induced by superconducting vortices in the high-critical-temperature (high-T c) magnetic superconductor EuRbFe4As4 Although the ground state of the Eu2+ moments in EuRbFe4As4 is helimagnetism below T m, neutron diffraction and magnetization experiments show a ferromagnetic hysteresis of the Eu2+ spin alignment. We demonstrate that the direction of the Eu2+ moments is dominated by the distribution of pinned vortices based on the critical state model. Moreover, we demonstrate the manipulation of spin texture by controlling the direction of superconducting vortices, which can help realize spin manipulation devices using magnetic superconductors.

5.
JBJS Case Connect ; 11(3)2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34473664

RESUMO

CASE: A 62-year-old woman with a medical history of nail-patella syndrome (NPS) presented with chronic right shoulder pain. Physical examination revealed that her right shoulder had a restricted range of motion. Radiograph of the shoulder revealed arthritic changes with glenohumeral joint space narrowing, inferior humeral head osteophytes, and posterior glenoid wear. The patient was successfully treated with total shoulder arthroplasty (TSA). The patient had an uneventful postoperative course and was satisfied with her quality of life at the 30-month follow-up. CONCLUSION: TSA may be successfully performed with careful reaming of the hypoplastic glenoid fossa in patients with NPS.

6.
Physiol Genomics ; 53(7): 285-294, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34097531

RESUMO

We investigated changes in rumen fermentation, peripheral blood metabolites and hormones, and hepatic transcriptomic dynamics in Holstein cows with and those without subacute ruminal acidosis (SARA) during the periparturient period. Sixteen multiparous Holstein cows were categorized in the SARA (n = 8) or non-SARA (n = 8) groups depending on whether they developed SARA during the 2 wk after parturition. Reticulo-ruminal pH was measured continuously throughout the study. Rumen fluid, blood, and liver tissue samples were collected at 3 wk prepartum and 2 and 6 wk postpartum, with an additional blood sample collected at 0 and 4 wk postpartum. The 1-h mean pH was depressed postpartum in both groups, whereas depression was more severe in the SARA group simultaneously with significantly longer duration of time (for pH <5.6 and 5.8). Significant expression of differentially expressed genes in liver tissue (DEGs; false discovery rate corrected P < 0.1) were identified only in the non-SARA group and were further analyzed by Ingenuity Pathway Analysis software. Among the top expressed DEGs, the hepatic genes encoding lipid and cholesterol secretion (APOA1, APOA4, and G0S2) and gluconeogenesis (PC, G6PC, and PCK1) were upregulated postpartum. In silico analysis revealed the significant postpartum activation of upstream regulators, such as INSR, PPARG, and PPARGC1A. These results suggested that hepatic transcriptomic responsiveness to postpartum metabolic load and hormones were likely discouraged in cows with SARA when compared with the significant activation of genes and signaling pathways for adequate metabolic adaption to postpartum high-grain diet feeding in Holstein cows without SARA.

7.
JSES Int ; 5(3): 493-499, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34136860

RESUMO

Background: Degenerative greater tuberosity (GT) changes are often associated with rotator cuff tears. However, little is known about the impact of GT morphology on surgical outcomes. The aim of this study was to examine the relationship between clinical and radiological outcomes, after rotator cuff repair, and GT morphology. Methods: We retrospectively investigated shoulders that underwent arthroscopic repair of nontraumatic full-thickness supra-/infraspinatus tears. The exclusion criteria were a lack of either radiographs or magnetic resonance images, revision surgery, partial repair, complications such as infection or dislocation, and follow-up < 2 years. GT morphology on radiographs was classified into 5 groups: normal, sclerosis, bone spur, roughness, and femoralization. The acromiohumeral interval (AHI) was measured on anteroposterior radiographs. Fatty degeneration of the cuff muscles was evaluated using the global fatty degeneration index (GFDI). Postoperative cuff integrity was classified using Sugaya's classification at 2 years after surgery. Clinical outcomes were assessed preoperatively and at postoperative 2 years with the Japanese Orthopaedic Association score and the University of California, Los Angeles shoulder rating scale. Results: The study included 220 shoulders in 212 patients (104 men and 108 women), with a mean age of 66 years (range 43-85). The mean follow-up period was 28 months (range, 24-60 months). Seven shoulders (3.2%) were classified as normal, 65 (29.5%) as sclerosis, 55 (25.0%) as bone spur, 78 (34.5%) as roughness, and 15 (6.8%) as femoralization. The preoperative AHI, in the roughness and femoralization groups, was significantly smaller than that in the sclerosis (P < .01) and bone spur groups (P < .001). The roughness and femoralization groups had a greater number of large tears (P = .006). In the roughness and femoralization groups, mean GFDI was significantly higher than that in the sclerosis group (P < .001 for both). Repaired cuff integrity was not different between all groups, respectively. Both Japanese Orthopaedic Association and University of California, Los Angeles scores improved postoperatively from 73.3 to 95.6 points and 18.2 to 34.0 points (P < .001 for both), respectively, and there were no significant differences between all groups, respectively. Conclusion: Roughness or femoralization of the GT was related to larger tears, with smaller AHI and higher GFDI. Repaired cuff integrity and clinical outcomes in shoulders with roughness or femoralization of the GT were not inferior to shoulders with the other types of GT morphologies in this study. Arthroscopic repair can be indicated for shoulders with advanced changes of the GT, if fatty degeneration of the cuff muscles is not severe.

8.
BMC Vet Res ; 17(1): 156, 2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33849520

RESUMO

BACKGROUND: The type 2 highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) has spread throughout countries of southeast Asia, where it has caused severe economic losses. Even countries presently free of PRRSV are at high risk for infection and spread of this virus. Some of these countries, including Japan, have broad epidemics of the local type 2 PRRSV, creating chronic pathogenicity in the domestic pig population. The present study aimed to evaluate the protective efficacy of immunity by infection with a Japanese field isolate, EDRD1, against heterologous challenge with a Vietnamese HP-PRRSV field strain. To this end, four groups of PRRSV-negative crossbreed piglets were used for a challenge study. Groups 1 and 2 were inoculated with EDRD1 via the intranasal route. After 26 days, Groups 2 and 3 were inoculated with HP-PRRSV via the same route. Group 4 served as an uninfected control. Blood and oral fluid samples were taken every 3-4 days after HP-PRRSV challenge; on day 16 post-challenge, all pigs were euthanized, and examined pathologically. RESULTS: The nucleotide sequence analysis of nonstructural protein 2 gene of EDRD1 and comparison with Vietnamese HP-PRRSV showed that the 39 amino acid deletion sites of EDRD1 was nearly in the same region as the 29 amino acid deletion sites of HP-PRRSV. Immunity conferred by inoculation with EDRD1 dramatically reduced viral load in the sera and tissues besides viral shedding (Group 2) compared with those in pigs infected only with HP-PRRSV (Group 3). The clinical signs and rectal temperature were significantly reduced, and the average daily weight gain was significantly improved in the EDRD1-inoculated pigs (Group 2) compared with the Group 3 pigs. Notably, no viral RNA was detected in various organs of the Group 2 pigs 16 days post-infection with HP-PRRSV, except in one pig. Therefore, the immunity induced by EDRD1 and its genetically close field isolates may play a role in reducing viremia caused by HP-PRRSV. CONCLUSIONS: The results of the present study demonstrate that pigs are highly protected against heterologous Vietnamese HP-PRRSV challenge by immunity against a Japanese local strain, EDRD1.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Vírus da Síndrome Respiratória e Reprodutiva Suína/patogenicidade , Administração Intranasal/veterinária , Animais , Anticorpos Antivirais/sangue , Síndrome Respiratória e Reprodutiva Suína/patologia , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Sus scrofa , Suínos , Carga Viral/veterinária , Proteínas não Estruturais Virais/genética , Viremia/veterinária
10.
Int J Surg Case Rep ; 76: 161-165, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33032048

RESUMO

BACKGROUND: Combination of choledochocele and extra-hepatic duct duplication is an extremely rare congenital abnormality. CASE PRESENTATION: The patient was an 81-year-old Japanese man. He visited the emergency room for severe abdominal colic pain. He was diagnosed with severe pancreatitis with cholelithiasis and treated conservatively by percutaneous trans-hepatic gallbladder drainage (PTGBD) for 4 months. Thereafter, he was transferred to our institute and cholangiography was performed via the PTGBD tube, revealing cholecysto- and choledocho-lithiasis. The cystic-duct joined the right hepatic duct with extra-hepatic bile duct duplication and the terminal bile duct flowed into the cystic papilla of Vater. The main pancreatic duct also joined into the cystic papilla. These observations confirmed choledochocele with extra-hepatic bile duct duplication. Surgical exploration was performed, and hepatico-jejunostomy with hepatic-ductplasty and cholecystectomy with choledocholithotomy were carried out. He was discharged and his course was uneventful. CONCLUSION: A very rare combined case of choledochocele with bile duct duplication, which would escalate the pancreatitis and cholangitis, was successfully treated. Their pathogeneses in relation to pancreaticobiliary maljunction is discussed.

11.
Inorg Chem ; 59(19): 14290-14295, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-32921044

RESUMO

It is generally difficult to quantify the amount of light elements in materials because of their low X-ray-scattering power, as this means that they cannot be easily estimated via X-ray analyses. Meanwhile, the recently reported layered superconductor, Sc20C8-xBxC20, requires a small amount of boron, which is a light element, for its structural stability. In this context, here, we quantitatively evaluate the optimal x value using both experimental and computational approaches. Using the high-pressure synthesis approach, which can maintain the starting composition even after sintering, we obtain the Sc20(C,B)8C20 phase by the reaction of the previously reported Sc15C19 and B (Sc15ByC19). Our experiments demonstrate that an increase in y values promotes the phase formation of the Sc20(C,B)8C20 structure; however, there appears to be an upper limit to the nominal y value to form this phase. The maximum critical temperature (Tc = 7.6 K) is found to correspond with the actual x value of x ≈ 5 under the assumption that the sample with the same Tc as the reported value (7.7 K) possesses the optimal x amount. Moreover, we construct the energy convex hull diagram by calculating the formation enthalpy based on first principles. Our computational results indicate that the composition of Sc20C4B4C20 (x = 4) is the most thermodynamically stable, which is reasonably consistent with the experimentally obtained value.

12.
J Vet Med Sci ; 82(10): 1529-1536, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32893200

RESUMO

We investigated changes in peripheral blood metabolites, oxidative stress markers (malondialdehyde, potential antioxidant capacity, and glutathione peroxidase [GPX]), and hepatic gene expression related to oxidative stress in Holstein cows with and without subacute ruminal acidosis (SARA) during the periparturient period. Eighteen multiparous Holstein cows were categorized into SARA (n=9) or non-SARA (n=9) groups depending on whether they developed SARA; reticulo-ruminal pH was <5.6 for more than 3 hr per day, during the 2 weeks after parturition. Blood and liver tissue samples were collected 3 weeks prepartum and 2 and 6 weeks postpartum, with an additional blood sample collected 0 and 4 weeks postpartum. Blood aspartate transaminase (AST) and nonesterified fatty acid (NEFA) increased significantly (P<0.05) after parturition in both groups. GPX activity decreased gradually after parturition in the SARA group. In the SARA group, gene expression of GPX 1 and microsomal glutathione S-transferase 3 (MGST3) decreased significantly (P<0.05), and expression of metallothionein 2A increased significantly (P<0.05) after parturition in the SARA group. Superoxide dismutase 1 and MGST3 decreased significantly (P<0.05) 2 weeks postpartum in the non-SARA group. Gene expression related to oxidative stress was negatively correlated with AST, NEFA and total ketone body levels. Therefore, the hepatic gene expression related to oxidative stress might change associated with a negative energy balance, and might relate the high oxidative stress in the SARA group during periparturient period.


Assuntos
Acidose/veterinária , Doenças dos Bovinos/metabolismo , Fígado/metabolismo , Estresse Oxidativo/fisiologia , Período Periparto/metabolismo , Rúmen/metabolismo , Acidose/sangue , Acidose/metabolismo , Animais , Biópsia/veterinária , Bovinos , Doenças dos Bovinos/sangue , Dieta/veterinária , Feminino , Expressão Gênica/fisiologia , Concentração de Íons de Hidrogênio , Lactação/metabolismo , Malondialdeído/metabolismo , Estresse Oxidativo/genética , Gravidez
13.
Front Vet Sci ; 7: 392, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32733925

RESUMO

African swine fever (ASF) is a devastating disease of swine and the most important disease for the pork industry. Since the outbreaks in 2007 in the Caucasian region, it has been spreading to the West and East quite swiftly. In this study we have analyzed the clinical signs and pathological features of the first outbreaks on ASF in Vietnam in 2019, caused by an isolate with 100% similarity to the genotype II (p72) isolates from Georgia in 2007 and China in 2018. The disease onset with a peracute to acute clinical course with high mortality. Some animals showed very unspecific clinical signs with other showing severe hyperthermia, respiratory distress, diarrhea, or vomit. Hemorrhagic splenomegaly and lymphadenitis were the main lesions observed at post mortem examination, with histopathological changes confirming the lymphoid depletion and multiorganic hemorrhages. Monocyte-macrophages were identified by means of immunohistochemical methods as the main target cell for the ASF virus in tissue sections.

14.
Inorg Chem ; 59(17): 12397-12403, 2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32845611

RESUMO

In this study, we succeeded in synthesizing new antiperovskite phosphides MPd3P (M = Ca, Sr, Ba) and discovered the appearance of a superconducting phase (0.17 ≤ x ≤ 0.55) in a solid solution (Ca1-xSrx)Pd3P. Three perovskite-related crystal structures were identified in (Ca1-xSrx)Pd3P, and a phase diagram was built on the basis of experimental results. The first phase transition from centrosymmetric (Pnma) to noncentrosymmetric orthorhombic (Aba2) occurred in CaPd3P near room temperature. The phase transition temperature decreased as Ca2+ was replaced with a larger-sized isovalent Sr2+. Bulk superconductivity at a critical temperature (Tc) of approximately 3.5 K was observed in a range of x = 0.17-0.55; this was associated with the centrosymmetric orthorhombic phase. Thereafter, a noncentrosymmetric tetragonal phase (I41md) remained stable for 0.6 ≤ x ≤ 1.0, and superconductivity was significantly suppressed as samples with x = 0.75 and 1.0 showed Tc values as low as 0.32 K and 57 mK, respectively. For further substitution with a larger-sized isovalent Ba2+, namely, (Sr1-yBay)Pd3P, the tetragonal phase continued throughout the composition range. BaPd3P no longer showed superconductivity down to 20 mK. Since the inversion symmetry of structure and superconductivity can be precisely controlled in (Ca1-xSrx)Pd3P, this material may offer a unique opportunity to study the relationship between inversion symmetry and superconductivity.

15.
J Vet Med Sci ; 82(7): 935-942, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32448816

RESUMO

The objective of the present study was to evaluate the cross-protective immunity between type 1 and type 2 porcine reproductive and respiratory syndrome virus (PRRSV) isolates in growing pigs. Japanese type 1 PRRSV, first isolated from a pig with respiratory disorders in a farm in 2009, exhibits unique genetic characteristics. The pathogenicity of a Japanese standard strain of type 2 PRRSV, EDRD1, in pigs immunized by the type 1 PRRSV isolate, Jpn EU 4-37 was determined by evaluating clinical signs, viremia, antibody response, and pathological lesions. Similarly, we evaluated the pathogenicity of Jpn EU 4-37 in pigs immunized by EDRD1 and compared the cross-protective immunity between these isolates. The EDRD1 challenge after Jpn EU 4-37 inoculation reduced viral clearance and shedding in pigs, compared to those treated with the EDRD1 single infection. On the other hand, the pathogenicity of Jpn EU 4-37 after EDRD1 infection did not differ significantly compared to non-immunized pigs treated with Jpn EU 4-37. Therefore, exposure to Jpn EU 4-37 could not induce enough immunity to reduce the viremia against subsequent infection by type 2 PRRSV. However, the immunity induced by Jpn EU 4-37 infection may play a role in reducing viremia caused by type 2 PRRSV. Moreover, the immunity induced by the EDRD1 and other genetically related viruses, which are broadly distributed in Japan, may not contribute to cross-protection against Jpn EU 4-37 as an emerging virus.


Assuntos
Síndrome Respiratória e Reprodutiva Suína/imunologia , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Administração Intranasal/veterinária , Animais , Anticorpos Antivirais/sangue , Síndrome Respiratória e Reprodutiva Suína/patologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Vírus da Síndrome Respiratória e Reprodutiva Suína/patogenicidade , RNA Viral , Organismos Livres de Patógenos Específicos , Sus scrofa , Suínos , Carga Viral/veterinária , Viremia/sangue , Viremia/veterinária
16.
J Dairy Sci ; 103(5): 4702-4716, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32171513

RESUMO

The authors have elected to retract this paper in accordance with the following points. The article as written contains misleading information and omits important details. Cows in this study were assigned to groups based on the current definition of subacute ruminal acidosis; they were housed on two different farms and fed two different sets of rations in this study. However, multiple farms were not described in the materials and methods and this was not accounted for in the statistical analysis as published. The diets shown in Table 1 were not actually fed to animals; rather, the proportions of ingredients listed represent an average of the two farms housing the cows. The authors regret the errors.


Assuntos
Acidose/veterinária , Bactérias/isolamento & purificação , Doenças dos Bovinos/microbiologia , Ácidos Graxos Voláteis/análise , Microbioma Gastrointestinal , Acidose/metabolismo , Acidose/microbiologia , Animais , Bactérias/genética , Bovinos , Doenças dos Bovinos/metabolismo , Dieta/veterinária , Feminino , Fermentação , Concentração de Íons de Hidrogênio , Parto , Gravidez , Prevotella/genética , Prevotella/isolamento & purificação , Rúmen/metabolismo , Rúmen/microbiologia
17.
J Pediatr Orthop B ; 29(4): 409-411, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32044858

RESUMO

Stress fractures of the first rib occur infrequently in adolescent athletes; therefore, there have been few case reports. Initial radiographs do not always lead to the diagnosis of first rib stress fractures. This study proposed a classification system and a possible mechanism for stress fractures of the first rib using three-dimensional computed tomography (3D-CT). The data of 10 stress fractures of the first rib in adolescent athletes obtained using 3D-CT between 2007 and 2018 were reviewed. Fractures of the first rib were classified according to the location and type of the fracture line. Stress fractures of the first rib were classified into three types: type 1, center-transverse fracture; type 2, center to posterior-oblique fracture; and type 3, posterior-transverse fracture. There were three type 1 fractures, five type 2 fractures, and two type 3 fractures. The fracture lines of types 1 and 2 were on the deep groove of the subclavian artery between the anterior and middle scalene muscle attachments, which is the thinnest and weakest portion of the first rib. However, the fracture line of type 3 was across the posterior part of the first rib and located slightly away from the deep groove of the subclavian artery. A 3D-CT classification of stress fractures of the first rib in adolescent athletes was proposed. Our results suggested that there are three types of the fracture and different mechanisms that cause this type of injury. This classification system helped to implement adequate conservative therapeutic plans based on the proposed mechanism.


Assuntos
Traumatismos em Atletas , Fraturas de Estresse , Costelas , Tomografia Computadorizada por Raios X/métodos , Adolescente , Traumatismos em Atletas/classificação , Traumatismos em Atletas/diagnóstico , Traumatismos em Atletas/etiologia , Traumatismos em Atletas/terapia , Fenômenos Biomecânicos/fisiologia , Tratamento Conservador/métodos , Feminino , Fraturas de Estresse/classificação , Fraturas de Estresse/diagnóstico , Fraturas de Estresse/etiologia , Fraturas de Estresse/fisiopatologia , Humanos , Imageamento Tridimensional/métodos , Masculino , Seleção de Pacientes , Costelas/diagnóstico por imagem , Costelas/lesões
18.
Int J Med Robot ; 16(2): e2062, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31913577

RESUMO

BACKGROUND: In recent years, there has been significant developments in surgical robots. Image-based sensing of surgical instruments, without the use of electric sensors, are preferred for easily washable robots. METHODS: We propose a method to estimate the three-dimensional posture of the tip of the forceps tip by using an endoscopic image. A convolutional neural network (CNN) receives the image of the tracked markers attached to the forceps as an input and outputs the posture of the forceps. RESULTS: The posture estimation results showed that the posture estimated from the image followed the electrical sensor. The estimated results of the external force calculated based on the posture also followed the measured values. CONCLUSION: The method which estimates the forceps posture from the image using CNN is effective. The mean absolute error of the estimated external force is smaller than the human detection limit.


Assuntos
Endoscópios , Endoscopia/métodos , Procedimentos Cirúrgicos Robóticos/instrumentação , Instrumentos Cirúrgicos , Algoritmos , Desenho de Equipamento , Humanos , Imageamento Tridimensional/métodos , Redes Neurais de Computação , Procedimentos Cirúrgicos Robóticos/métodos , Software , Estresse Mecânico
19.
Int J Med Robot ; 16(2): e2051, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31710158

RESUMO

BACKGROUND: Sensing the grasping force and displaying the force for the operator are important for safe operation in robot-assisted surgery. Although robotic forceps that senses the force by force sensors or driving torque of electric motors is proposed, the force sensors and the motors have some problems such as increase in weight and difficulty of the sterilization. METHOD: We developed a pneumatically driven robotic forceps that estimates the grasping torque and display the magnified torque for the operator. The robotic forceps has a master device and a slave robot, and they are integrated. In the slave side, the grasping torque is estimated by the pressure change in the pneumatic cylinder. A pneumatic bellows display the torque through a linkage. RESULTS: We confirmed that the slave robot follows the motion of the master, and the grasping torque is estimated in the accuracy of 7 mNm and is magnified and displayed for the operator. CONCLUSIONS: The pneumatically driven robotic forceps has the capability in the estimation of the grasping torque and display of the torque. Regarding future work, the usability and fatigues of the surgeons must be evaluated.


Assuntos
Procedimentos Cirúrgicos Robóticos/instrumentação , Cirurgia Assistida por Computador/instrumentação , Instrumentos Cirúrgicos , Torque , Desenho de Equipamento , Força da Mão , Humanos , Microcirurgia , Movimento (Física) , Estresse Mecânico , Interface Usuário-Computador
20.
Inorg Chem ; 58(22): 15629-15636, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31661255

RESUMO

The discovery of nearly room-temperature superconductivity in superhydrides has motivated further materials research for conventional superconductors. To realize the moderately high critical temperature (Tc) in materials containing light elements, we explored new superconducting phases in a scandium borocarbide system. Here, we report the observation of superconductivity in a new ternary Sc-B-C compound. The crystal structure, which was determined through a Rietveld analysis, belongs to tetragonal space group P4/ncc. By complementarily using the density functional theory calculations, a chemical formula of the compound was found to be expressed as Sc20C8-xBxC20 (x = 1 or 2). Interestingly, a small amount of B is essential to stabilize the present structure. Our experiments revealed the typical type-II superconductivity at Tc = 7.7 K. Additionally, we calculated the density of states within a first-principles approach and found that the contribution of the Sc-3d orbital was mainly responsible for the superconductivity.

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